The Supreme Court  December 23, in Trump v Illinois, on a 5 -4 vote, put a stop to a singularly Trumpian way to fan the flames of mass deportation. The court barred the administration from using the National Guard for the purposes intended by the administration, which was a very visible and direct (and cosmetic) enforcer of deportation.

Administration said that it could mobilize the National Guard on the grounds that “regular forces” were “unable with the regular forces to execute the laws of the United States.”  It sought to thread a legal needle.

In order to mobilize the National Guard of, say, Indiana and deploy them in, say, Chicago, the president needed to federalize the Indiana National Guard and then deploy them. This is allowed in 10 U.S.C. §12406(3). The majority collectively found (there was not one majority opinion) that this step violated two barriers:

First, given as the military had not been involved in Chicago, the administration argued that civilian law enforcement agencies such as ICE were in effect “regular forces” and that they were “unable to execute” the laws. The court, however, defined “regular forces” as the military. But even if the majority of the Court had agreed with the administration that ICE, etc. were part of the regular forces, the mobilized National Guard could not have been used to patrol the streets, as they did in DC, and arrest but used only in a supportive role (like guarding buildings).

Then the majority shot another bullet into the administration’s case. The use of the military (for that is what the National Guard units had become) was only permitted either when Congress permits it (a provision in the Posse Comitative Act) or under the Insurrection Act, but the president did not invoke the Insurrection Act. He did not very likely due to the absence of an insurrection or rebellion and due to DoD resistance.

the court, further, said that protecting building is not an essential aspect “execut[ing] the laws.”

The administration sought to bolster its case by citing Article 2 of the constitution giving the president authority over the armed forces and requiring the president to ensure that the laws are faithfully executed. The problem here is that Article 2 has been used extremely sparingly, and then only when the risk of or actual violence is very well defined – Little Rock in 1957 and the Los Angeles riots in 1992.  This has certainly not been the case with the nature of local protests against ICE actions.